1. Field of the Invention
The present invention relates to a clutch device and a differential device using the same.
2. Description of the Related Art
A differential device, disclosed in Japanese Patent Application Laid-Open No. 2004-100924, is comprised of a diff case, a bevel type differential mechanism connected to the diff case, a differential limiting mechanism forming a clutch device, an electromagnetic actuator and others. The differential mechanism includes a side gear spline coupled to an output shaft, a pinion gear held in meshing engagement with the side gear, and a pinion shaft supported with the diff case and supporting the pinion gear. The electromagnetic actuator is comprised of a plunger and an electromagnetic solenoid operative to move the plunger using magnetic force to actuate the differential limiting mechanism. Also, a ring gear is fixedly supported on the diff case applied with drive power from a prime mover.
With such a differential device described above, a magnetic flux path generated by the electromagnetic actuator including the plunger is closed only in this actuator. Thus the attempt of installing this differential device on a vehicle occurs interference between the electromagnetic actuator and a bearing with which the diff case is supported. Since this restricts a variety of models (of differential device) to which the electromagnetic actuator can be installed, the clutch device involving the electromagnetic actuator needs to have a large size in structure.
With such a differential device described above, further, the differential limiting mechanism is disposed in a rotary system and the electromagnetic actuator is disposed in a stationary system. The clutch ring, playing a role as a side member of the differential limiting mechanism (mating clutch), is positioned on the diff case with respect to an axial direction, and the plunger, playing a role as one member of the electromagnetic actuator, is held in abutment with the electromagnetic solenoid and positioned in the axial direction.
The positioning of the clutch ring and the plunger independently from each other in such a way leaves a clearance between these component parts. Since this increases a stroke needed for the plunger of the electromagnetic solenoid to move in an increased stroke by that extent, the electromagnetic solenoid needs to have a large size in structure.